# Iroh

> A peer-to-peer QUIC library for establishing direct connections between devices. Built in Rust by n0-computer.

## Overview

Iroh is a library for establishing the most direct QUIC connection possible between two devices. It provides "dial by public key" functionality, where you connect to nodes using their NodeId (32-byte ed25519 public key) rather than IP addresses. The library handles NAT traversal, hole punching, and relay fallbacks automatically.

Iroh is compiled & tested for nearly all common platforms: Windows, MacOS, Linux, Android, iOS, etc. It runs on devices as small as an ESP32, as well as datacenter-grade servers.

## Key Features

- **Direct P2P connections**: Establishes direct QUIC connections whenever possible
- **NAT traversal**: Automatic hole punching and relay server fallback
- **Cryptographic identity**: Each node identified by ed25519 public key (NodeId)
- **QUIC-based**: Built on QUIC for encryption, authentication, and stream multiplexing
- **Composable protocols**: Compose multiple protocols for pluggable functionality from a community-driven set

## Core Documentation

- [API Reference](https://docs.rs/iroh/latest/iroh/): Complete Rust API documentation for the core iroh library
- [Overview](https://www.iroh.computer/docs/overview): High-level introduction to iroh's architecture and benefits
- [Quickstart](https://www.iroh.computer/docs/quickstart): Build a simple peer-to-peer file transfer tool
- [Getting Started](https://www.iroh.computer/docs/): Main documentation hub with guides and examples

## Architecture & Concepts

- [Connection Establishment](https://docs.rs/iroh/latest/iroh/#connection-establishment): How iroh establishes connections via relay servers and direct addressing
- [Encryption](https://docs.rs/iroh/latest/iroh/#encryption): TLS encryption using node SecretKey/PublicKey pairs
- [Relay Servers](https://docs.rs/iroh/latest/iroh/#relay-servers): How relay servers ensure connectivity and assist with hole punching
- [Connections and Streams](https://docs.rs/iroh/latest/iroh/#connections-and-streams): QUIC streams, ALPNs, and connection management
- [Node Discovery](https://docs.rs/iroh/latest/iroh/#node-discovery): DNS-based discovery services for finding nodes

## Core API

- [Endpoint](https://docs.rs/iroh/latest/iroh/endpoint/struct.Endpoint.html): Central struct for managing an iroh node and creating connections
- [NodeAddr](https://docs.rs/iroh/latest/iroh/struct.NodeAddr.html): Network addressing information combining NodeId, relay URLs, and direct addresses
- [Connection](https://docs.rs/iroh/latest/iroh/endpoint/struct.Connection.html): QUIC connection with bi-directional and uni-directional stream support
- [SecretKey/PublicKey](https://docs.rs/iroh/latest/iroh/struct.SecretKey.html): Cryptographic keys for node identity and authentication

## Protocols & Extensions

Protocols are listed at https://iroh.computer/proto.

- [iroh-blobs](https://github.com/n0-computer/iroh-blobs): Content-addressed blob transfer using BLAKE3 hashing
- [iroh-gossip](https://github.com/n0-computer/iroh-gossip): Publish-subscribe overlay networks
- [iroh-docs](https://github.com/n0-computer/iroh-docs): Eventually-consistent key-value store
- [iroh-willow](https://github.com/n0-computer/iroh-willow): Implementation of the Willow protocol
- [Protocol Router](https://docs.rs/iroh/latest/iroh/protocol/): Tools for routing incoming requests to appropriate protocol handlers

## Examples & Tutorials

- [Echo Example](https://github.com/n0-computer/iroh/blob/main/iroh/examples/echo.rs): Simple bidirectional communication example
- [Examples Directory](https://github.com/n0-computer/iroh/tree/main/iroh/examples): Collection of usage examples
- [Tour](https://www.iroh.computer/docs/tour): High-level architectural overview
- [Layers](https://www.iroh.computer/docs/layers): Understanding iroh's distributed systems toolkit

## Development & Integration

- [Quickstart Tutorial](https://www.iroh.computer/docs/quickstart): Build a file transfer tool step-by-step
- [Wasm/Browser Support](https://www.iroh.computer/docs/wasm-browser-support): WebAssembly and browser compatibility
- [iroh-ffi](https://github.com/n0-computer/iroh-ffi): FFI bindings for other languages
- [Test Utils](https://docs.rs/iroh/latest/iroh/test_utils/): Internal utilities for testing iroh applications

## Infrastructure & Ecosystem

- [Relay Server](https://github.com/n0-computer/iroh/tree/main/iroh-relay): Production relay server implementation
- [DNS Server](https://github.com/n0-computer/iroh/tree/main/iroh-dns-server): DNS discovery service running at dns.iroh.link
- [Network Report](https://docs.rs/iroh/latest/iroh/net_report/): Network condition analysis and NAT detection
- [Performance Monitoring](https://perf.iroh.computer): Continuous performance measurement

## Reference Materials

- [FAQ](https://www.iroh.computer/docs/faq): Frequently asked questions
- [Roadmap](https://www.iroh.computer/roadmap): Future development plans
- [Protocol Registry](https://www.iroh.computer/proto): Directory of iroh protocols

## Community & Resources

- [GitHub Repository](https://github.com/n0-computer/iroh): Source code and issue tracking
- [Awesome Iroh](https://github.com/n0-computer/awesome-iroh): Community projects and resources
- [License](https://github.com/n0-computer/iroh/blob/main/LICENSE-APACHE): Apache 2.0 / MIT dual license